This research will be directed to the identification, purification, and characterization of the enzymes involved in glycoprotein processing reactions. These reactions must play a major role in determining the final structures of the oligosaccharide side chains of mammalian glycoproteins. Assays will be developed utilizing natural substrates and carbon-14 labeled oligosaccharides synthesized enzymatically. Attempts will be made to identify any mechanisms that may regulate or control the processing enzymes. Since the oligosaccharide side chains present of mammalian glycoproteins have been implicated in a variety of different biological functions, this research should contribute to a better understanding of the relationship between structure of the oligosaccharide chains and biological function. Processing reactions will be identified in mammalian liver and in fibroblasts grown in culture. Growing and non-growing, normal and transformed cells will be compared as to enzyme activities.